1. Field of the Invention
Aspects of the present invention relate to a battery management system and a battery management method. More particularly, aspect of the present invention relate to a battery management system for a vehicle utilizing electrical energy.
2. Description of the Related Art
Vehicles using a gasoline or diesel oil internal combustion engines have caused serious air pollution. Accordingly, various efforts for developing electric or hybrid vehicles have recently been made to reduce air pollution.
An electric vehicle uses an electric motor run by electrical energy output by a power source. Many electric vehicles use a battery formed by one battery pack comprising a plurality of rechargeable/dischargeable secondary cells, as a power source. Electric vehicles benefit the environment because they emit fewer greenhouse gasses and produce less noise.
A hybrid vehicle commonly refers to a gasoline-electric hybrid vehicle that uses gasoline to power an internal combustion engine, and an electric battery to power an electric motor. Recently, hybrid vehicles using an internal combustion engine and fuel cells, and hybrid vehicles using a battery and fuel cells, have been developed. The fuel cells directly obtain electrical energy by generating a chemical reaction between hydrogen and oxygen.
In battery powered vehicles, the number of rechargeable batteries (cells) has been increased to improve the charge carrying capacity and efficiency thereof. A cell balancing control method capable of efficiently managing a plurality of coupled cells and/or battery packs is needed for a battery management system (hereinafter, referred to as “BMS”).
To measure a battery's voltage, a differential amplification terminal using a differential amplifier has been used. Such a differential amplification terminal includes at least one resistor, and detects a battery voltage by amplifying a voltage difference input into an input terminal thereof, according to a gain corresponding to a resistance of at least one resistor.
A conventional voltage detecting unit for detecting a battery voltage is required for each of the cells of the battery. As such, since the voltage detecting unit is respectively coupled to the cells of the battery, the number of voltage detecting units has increased as the number of cells has been increased. Accordingly, when the battery voltage is detected using a conventional battery voltage detecting unit, there are problems in that the cost thereof is increased. It is also difficult to determine abnormalities in the circuits of the battery voltage detecting unit, because of small current leakages generated from the voltage detecting unit cell couplings, respectively coupled to the battery cells, and the overall complexity of the circuit structure.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.